A. Field of the Invention
The present invention relates to a connector structure and more particularly, but not exclusively to a connector for locking adjacent ends of concrete pile sections.
B. Description of the Prior Art
The present invention relates to an improved connector structure of the type as disclosed in my U.S. Pat. No. 3,422,630 issued Jan. 21, 1969 and entitled "Concrete Pile Construction". The state of the art in the last few years and relating to concrete pile construction has been quite stable in that these piles have remained substantially of the same type construction, being circular or hexagonal in cross-section and being formed of reinforced concrete. To date, there are only two connector joints known to the Applicant, one of which is that as disclosed in my above-mentioned U.S. Pat. and the other as disclosed in U.S. Pat. No. 3,104,532.
From a further analysis and experimentation of such connector structures, it has been found that various problems exist with these type joints. For example, it has been found that the locking rods of circular cross-section in the locking joint have a tendency to fail when the flange section of the female connector is not of sufficient thickness. When the joint is subjected to a traction load, the load distribution on the locking rod gives a resultant load component which is at an angle relative to the longitudinal axis of the pile for the reason that the locking rod is of a circular cross-section. From a vector analysis, it can be seen that a force acting downwardly, transverse to the longitudinal axis of the locking rod, would have a resultant vector substantially oriented towards 45.degree. to the said vertical axis. This resultant force is a force which is lost and which can also be damaging to the joint structure.